Incandescent lamp



(No Model.)

' G. .J. VAN DEPOELE.

INOANDBSGENT LAMP. No. 323,983. Patented Aug. 11, 1885,

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CHARLES J. VAN DEPOELE, OF CHICAGO, ILLINOIS.

INCAN DESC ENT LAMP.

SPECIFICATION forming part of Letters Patent No. 323,983, dated August11, 188i,

Application filed November 3, 1884 (No model.)

To all whom it ma 0011/06/70.

Be it known that I, CHARLES J. VAN DE- POELE, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements inIncandescent Lamps, of which the following is a specification, referencebeing had to the accompanyingdrawings.

The present invention relates to improvements in filaments or conductorsfor electric lamps of the incandescent type; and it consists in theproduction of a filament of large surface and high resistance, whereby Iam en-. ahled to construct and operate incandescent lamps of muchgreater candle-power than have heretofore been constructed, and also touse currents of higher tension than has previously been foundpracticable.

It has been usual hitherto to form the inoandescing filament ot' acontinuous conductor through which current of a certain intensity andelectro-motive force was caused to pass. As usually constructed thefilament is neces sarily of very small cross'section, and thereforeextremely delicate and easily broken, limiting its heat-enduringcapacity to a comparatively low temperature, occasionin g a smallerefficiency than if it were practicable to operate the lamp with acurrent of electromotive force. sufficient to heat a filament of thesame size to a higher degree. The aim of the present invention is toprovide a conducting medium which is not homogeneously continuous, andwhich, by virtue of its construction, will safely carry a current of anintensity and electrc-motive force much greater than is at present used.

The method of manufacture is as follows, viz. Loose cotton, silk, hemp,manila, or other fibers are assembled or arranged in proximity to eachother in the form of an open untwisted band or tress having its fibersso interlaced with each other as an ordinary process of combing wouldleave them, these bands, tresses, or skeins being of greater or lessthickness, width, and length, but in all cases the individual fibers areto be only in loose contact with each other.

I do not. limit myself to the size or length of fiber in the materialused, as that will be selected according to the effect desired.

In practice, bands are formed of, say, three inches in length, having across-section or" onesixteenth to one-halfinch or any other proportionsfound desirable. The bands thus formed are properly carbonized, afterwhich they are cut up into length suitable to he placed between theprongs or clamps attached to the conductors leading into the lamp.

The connection between the incandcscing filament and thesupportingconductors may be rendered more perfect by the application ofany cai bonizable cement. The conductors and filament haviugbeenassembled, they are, with the exception of the ends of the wires,inolosed in a bulb or flask from which the air is exhausted in anysuitable or wellknown manner.

It will be understood from the foregoing that it is designed to assemblea comparatively large quantity of fiber in sufficiently close proximitythat portions of said fibers will touch adjoining fibers, and therebyafford continuous passage to the current without necessitating theabsolute continuity of each member of the strand. The individual fiberswill not generally extend through the entire length of the conductor,nor is it requisite that all the fibers should be parallel to eachother, since they may be crosswise, oblique, parallel, or spiral, or bebrought together in any way that will, by making a large number ofcontacts, afford numerous paths for the current, each of very smallcross-section, and therefore of high resistance, and thereby produce afilament of large surface having a high resistance and greatheat-enduring, and, consequently, light-giving, capacity. The reasonthis filament will stand more heat than the ordinary so-calledhomogeneous continuous filament is that the former, being composed of alarge number of small conductingpaths, is better able to accommodate theexpansion and contraction than the ordinary filament formed of onecontinuous and homogeneousconductor. Another advantage gained is thatthe light-giving capacity-of the improved fila ment is greater with thesame current, which is due to the iufinitesimally small surface of eachindividual conductor, which is more readily heated, and the aggregatenumber of individual fibers forms a much larger exposed surface than itis possible to use in the form of a single homogeneouslycontinuousconductor.

I do not limit myself to any special disposition or mode of mounting theconducting media, since aln'iost any of the well-known ways will producegood results; but, for the sake of illustration, 1 have shown in theaccompanying drawings an incandescent lamp of ordinary i'orm between theterminals A A of which, in suitable clamps, B, I secure my improvedfilament U.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. An incandescing filament consisting of a non-homogeneous aggregationof carbonized fibers, substantially as described.

2. An incandescing filament composed of an indefinite number of smallindividual fibers not necessarily continuous throughout the entirelength of the filament, but intermingling with each other and atiordingnumerous conducting-passages through the conducting medium,substantially as set forth.

3. An incandescing filament composed of an aggregation of short fibersinterlaced so as to form numerous continuous passages throughout theentire filament, said fibers being united at their extremities, wherebythe filament is adapted to be connected by suit able clamps with theline-wires entering the lamp, substantially as set forth.

In testimony whereof I ai'fix my signature in presence of two witnesses.

CHARLES J. VAN DEPOELE.

Witnesses:

E. S. BALLOU, THEO. P. BAILEY.

